Global occurrence: Oceania – Australasia | Eurasia – Europe | Americas – North America (incl Mexico) | Americas – South and Central America | Arctic.  Substrate: rock – calcareous, calciferous, basic.  Life habit: lichenized (mutualistic with algal photobionts).  Thallus: crustose (crustaceous) – episubstratal – unspecified; thallus: cracked, fissured, fractured, rimose | compartimentized – areolate, squamulate; [th] upper surface: white(ish) | brown(ish) yellow (ochraceous, ochre) | grey(ish) white | brown(ish) white; [th marginal and upper surface] specific structures: absent.  Ascomata: absent | present; ascoma: apothecial, apothecioid – hymenial; ascoma [mm]: (median) 1.0; ascoma: immersed, innate | subsessile, subimmersed, adnate, semi-immersed, emergent; [ascm, if apoth] disc, mazaedium: black(ish); [ascm, if apoth] disc, mazaedium: epruinose | pruinose; [ascm, if apoth] disc, mazaedium pruina: scarce, sparse, fine.  Asci: lecanoralean; [asc] tholus: thickened; [asc] tholus amyloidity (iodine reaction): absent; [asp] septa: absent – spore lumen unilocular, monolocular; [asp] pigmentation: hyaline, colourless.  Secondary metabolites: present, aspicilin.  Primary photobiont: present, chlorophytaceous – trebouxiaceous, chlorococcoid.  Secondary photobionts (eg in cephalodia): absent.